Bioinspired Total Synthesis of (+)-Kopsiyunnanine B

Abstract

The first enantioselective total synthesis of kopsiyunnanine B, which has a unique folded and complex pentacyclic structure containing six contiguous chiral centers, has been achieved along our originally proposed biosynthetic pathway. The key reaction of this synthesis includes a bioinspired cascade that builds three ring structures and three chiral centers in one step and features the stereoselective reduction of a β-acrylate and oxidation to an oxindole.

Keywords: Kopsia alkaloid; bioinspired reaction; cascade reaction; oxindole alkaloid; total synthesis.